To increment a cell reference by 9 rows in Excel:

Use the following formula:
Here's how it works:

1. ROW(A7) returns the row number of cell A7, which is 7.
2. Subtracting 7 from 7 gives you 0, which is the offset you need to start at row 30.
3. Multiplying 0 by 9 gives you 0, so you start at row 30.
4. Adding 30 to 0 gives you 30, which is the row number you need to reference in the 'Data' sheet.
5. The INDIRECT function takes this string and returns the value of the cell it refers to.

When you copy this formula down to cells A8, A9, etc., the ROW function will return the appropriate row number for each cell, and the formula will adjust accordingly.

So, for example, in cell A8, ROW(A8) returns 8, so the formula becomes:

Which evaluates to:

And returns the value of cell A39 in the 'Data' sheet.

I hope this helps! Let me know if you have any questions.